2 * RAM Oops/Panic logger
4 * Copyright (C) 2010 Marco Stornelli <marco.stornelli@gmail.com>
5 * Copyright (C) 2011 Kees Cook <keescook@chromium.org>
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * version 2 as published by the Free Software Foundation.
11 * This program is distributed in the hope that it will be useful, but
12 * WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
23 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
25 #include <linux/kernel.h>
26 #include <linux/err.h>
27 #include <linux/module.h>
28 #include <linux/pstore.h>
29 #include <linux/time.h>
31 #include <linux/ioport.h>
32 #include <linux/platform_device.h>
33 #include <linux/slab.h>
34 #include <linux/pstore_ram.h>
36 #define RAMOOPS_KERNMSG_HDR "===="
37 #define MIN_MEM_SIZE 4096UL
39 static ulong record_size
= MIN_MEM_SIZE
;
40 module_param(record_size
, ulong
, 0400);
41 MODULE_PARM_DESC(record_size
,
42 "size of each dump done on oops/panic");
44 static ulong mem_address
;
45 module_param(mem_address
, ulong
, 0400);
46 MODULE_PARM_DESC(mem_address
,
47 "start of reserved RAM used to store oops/panic logs");
49 static ulong mem_size
;
50 module_param(mem_size
, ulong
, 0400);
51 MODULE_PARM_DESC(mem_size
,
52 "size of reserved RAM used to store oops/panic logs");
54 static int dump_oops
= 1;
55 module_param(dump_oops
, int, 0600);
56 MODULE_PARM_DESC(dump_oops
,
57 "set to 1 to dump oopses, 0 to only dump panics (default 1)");
59 static int ramoops_ecc
;
60 module_param_named(ecc
, ramoops_ecc
, int, 0600);
61 MODULE_PARM_DESC(ramoops_ecc
,
62 "set to 1 to enable ECC support");
64 struct ramoops_context
{
65 struct persistent_ram_zone
**przs
;
66 phys_addr_t phys_addr
;
72 unsigned int max_count
;
73 unsigned int read_count
;
74 struct pstore_info pstore
;
77 static struct platform_device
*dummy
;
78 static struct ramoops_platform_data
*dummy_data
;
80 static int ramoops_pstore_open(struct pstore_info
*psi
)
82 struct ramoops_context
*cxt
= psi
->data
;
88 static ssize_t
ramoops_pstore_read(u64
*id
, enum pstore_type_id
*type
,
89 struct timespec
*time
,
91 struct pstore_info
*psi
)
94 struct ramoops_context
*cxt
= psi
->data
;
95 struct persistent_ram_zone
*prz
;
97 if (cxt
->read_count
>= cxt
->max_count
)
100 *id
= cxt
->read_count
++;
101 prz
= cxt
->przs
[*id
];
103 /* Only supports dmesg output so far. */
104 *type
= PSTORE_TYPE_DMESG
;
105 /* TODO(kees): Bogus time for the moment. */
109 /* Update old/shadowed buffer. */
110 persistent_ram_save_old(prz
);
111 size
= persistent_ram_old_size(prz
);
112 *buf
= kmalloc(size
, GFP_KERNEL
);
115 memcpy(*buf
, persistent_ram_old(prz
), size
);
120 static size_t ramoops_write_kmsg_hdr(struct persistent_ram_zone
*prz
)
123 struct timeval timestamp
;
126 do_gettimeofday(×tamp
);
127 hdr
= kasprintf(GFP_ATOMIC
, RAMOOPS_KERNMSG_HDR
"%lu.%lu\n",
128 (long)timestamp
.tv_sec
, (long)timestamp
.tv_usec
);
130 len
= hdr
? strlen(hdr
) : 0;
131 persistent_ram_write(prz
, hdr
, len
);
137 static int ramoops_pstore_write(enum pstore_type_id type
,
138 enum kmsg_dump_reason reason
,
141 size_t size
, struct pstore_info
*psi
)
143 struct ramoops_context
*cxt
= psi
->data
;
144 struct persistent_ram_zone
*prz
= cxt
->przs
[cxt
->count
];
147 /* Currently ramoops is designed to only store dmesg dumps. */
148 if (type
!= PSTORE_TYPE_DMESG
)
151 /* Out of the various dmesg dump types, ramoops is currently designed
152 * to only store crash logs, rather than storing general kernel logs.
154 if (reason
!= KMSG_DUMP_OOPS
&&
155 reason
!= KMSG_DUMP_PANIC
)
158 /* Skip Oopes when configured to do so. */
159 if (reason
== KMSG_DUMP_OOPS
&& !cxt
->dump_oops
)
162 /* Explicitly only take the first part of any new crash.
163 * If our buffer is larger than kmsg_bytes, this can never happen,
164 * and if our buffer is smaller than kmsg_bytes, we don't want the
165 * report split across multiple records.
170 hlen
= ramoops_write_kmsg_hdr(prz
);
171 if (size
+ hlen
> prz
->buffer_size
)
172 size
= prz
->buffer_size
- hlen
;
173 persistent_ram_write(prz
, cxt
->pstore
.buf
, size
);
175 cxt
->count
= (cxt
->count
+ 1) % cxt
->max_count
;
180 static int ramoops_pstore_erase(enum pstore_type_id type
, u64 id
,
181 struct pstore_info
*psi
)
183 struct ramoops_context
*cxt
= psi
->data
;
185 if (id
>= cxt
->max_count
)
188 persistent_ram_free_old(cxt
->przs
[id
]);
193 static struct ramoops_context oops_cxt
= {
195 .owner
= THIS_MODULE
,
197 .open
= ramoops_pstore_open
,
198 .read
= ramoops_pstore_read
,
199 .write
= ramoops_pstore_write
,
200 .erase
= ramoops_pstore_erase
,
204 static int __init
ramoops_probe(struct platform_device
*pdev
)
206 struct device
*dev
= &pdev
->dev
;
207 struct ramoops_platform_data
*pdata
= pdev
->dev
.platform_data
;
208 struct ramoops_context
*cxt
= &oops_cxt
;
212 /* Only a single ramoops area allowed at a time, so fail extra
218 if (!pdata
->mem_size
|| !pdata
->record_size
) {
219 pr_err("The memory size and the record size must be "
224 pdata
->mem_size
= rounddown_pow_of_two(pdata
->mem_size
);
225 pdata
->record_size
= rounddown_pow_of_two(pdata
->record_size
);
227 /* Check for the minimum memory size */
228 if (pdata
->mem_size
< MIN_MEM_SIZE
&&
229 pdata
->record_size
< MIN_MEM_SIZE
) {
230 pr_err("memory size too small, minimum is %lu\n",
235 if (pdata
->mem_size
< pdata
->record_size
) {
236 pr_err("The memory size must be larger than the "
241 cxt
->max_count
= pdata
->mem_size
/ pdata
->record_size
;
243 cxt
->size
= pdata
->mem_size
;
244 cxt
->phys_addr
= pdata
->mem_address
;
245 cxt
->record_size
= pdata
->record_size
;
246 cxt
->dump_oops
= pdata
->dump_oops
;
247 cxt
->ecc
= pdata
->ecc
;
249 cxt
->przs
= kzalloc(sizeof(*cxt
->przs
) * cxt
->max_count
, GFP_KERNEL
);
252 dev_err(dev
, "failed to initialize a prz array\n");
256 for (i
= 0; i
< cxt
->max_count
; i
++) {
257 size_t sz
= cxt
->record_size
;
258 phys_addr_t start
= cxt
->phys_addr
+ sz
* i
;
260 cxt
->przs
[i
] = persistent_ram_new(start
, sz
, cxt
->ecc
);
261 if (IS_ERR(cxt
->przs
[i
])) {
262 err
= PTR_ERR(cxt
->przs
[i
]);
263 dev_err(dev
, "failed to request mem region (0x%zx@0x%llx): %d\n",
264 sz
, (unsigned long long)start
, err
);
269 cxt
->pstore
.data
= cxt
;
270 cxt
->pstore
.bufsize
= cxt
->przs
[0]->buffer_size
;
271 cxt
->pstore
.buf
= kmalloc(cxt
->pstore
.bufsize
, GFP_KERNEL
);
272 spin_lock_init(&cxt
->pstore
.buf_lock
);
273 if (!cxt
->pstore
.buf
) {
274 pr_err("cannot allocate pstore buffer\n");
278 err
= pstore_register(&cxt
->pstore
);
280 pr_err("registering with pstore failed\n");
285 * Update the module parameter variables as well so they are visible
286 * through /sys/module/ramoops/parameters/
288 mem_size
= pdata
->mem_size
;
289 mem_address
= pdata
->mem_address
;
290 record_size
= pdata
->record_size
;
291 dump_oops
= pdata
->dump_oops
;
293 pr_info("attached 0x%lx@0x%llx (%ux0x%zx), ecc: %s\n",
294 cxt
->size
, (unsigned long long)cxt
->phys_addr
,
295 cxt
->max_count
, cxt
->record_size
,
296 ramoops_ecc
? "on" : "off");
301 kfree(cxt
->pstore
.buf
);
303 cxt
->pstore
.bufsize
= 0;
306 for (i
= 0; cxt
->przs
[i
]; i
++)
307 persistent_ram_free(cxt
->przs
[i
]);
313 static int __exit
ramoops_remove(struct platform_device
*pdev
)
316 /* TODO(kees): We cannot unload ramoops since pstore doesn't support
319 struct ramoops_context
*cxt
= &oops_cxt
;
321 iounmap(cxt
->virt_addr
);
322 release_mem_region(cxt
->phys_addr
, cxt
->size
);
325 /* TODO(kees): When pstore supports unregistering, call it here. */
326 kfree(cxt
->pstore
.buf
);
327 cxt
->pstore
.bufsize
= 0;
334 static struct platform_driver ramoops_driver
= {
335 .remove
= __exit_p(ramoops_remove
),
338 .owner
= THIS_MODULE
,
342 static int __init
ramoops_init(void)
345 ret
= platform_driver_probe(&ramoops_driver
, ramoops_probe
);
346 if (ret
== -ENODEV
) {
348 * If we didn't find a platform device, we use module parameters
349 * building platform data on the fly.
351 pr_info("platform device not found, using module parameters\n");
352 dummy_data
= kzalloc(sizeof(struct ramoops_platform_data
),
356 dummy_data
->mem_size
= mem_size
;
357 dummy_data
->mem_address
= mem_address
;
358 dummy_data
->record_size
= record_size
;
359 dummy_data
->dump_oops
= dump_oops
;
360 dummy_data
->ecc
= ramoops_ecc
;
361 dummy
= platform_create_bundle(&ramoops_driver
, ramoops_probe
,
363 sizeof(struct ramoops_platform_data
));
366 ret
= PTR_ERR(dummy
);
374 static void __exit
ramoops_exit(void)
376 platform_driver_unregister(&ramoops_driver
);
380 module_init(ramoops_init
);
381 module_exit(ramoops_exit
);
383 MODULE_LICENSE("GPL");
384 MODULE_AUTHOR("Marco Stornelli <marco.stornelli@gmail.com>");
385 MODULE_DESCRIPTION("RAM Oops/Panic logger/driver");